Vehicles propelled by tracks or so-called “tracked vehicles” are useful in travelling over terrain which is inaccessible to vehicles driven by wheels. For example, tracked vehicles such as All Terrain Vehicles (ATV's) are capable of travelling over steep rolling terrain or terrain littered with rocks and other debris. Such vehicles are particularly useful in mineral exploration and in search and rescue work. Other tracked vehicles such as snowmobiles are capable of travelling over snow and ice and are useful for carrying out work in the arctic and also in search and rescue work.
Existing tracked vehicles are usually restricted in the type of terrain over which they are capable of travelling. For example, existing snowmobiles are usually constructed to travel on ice or snow but not on pavement. Existing ATV's are usually restricted to travel on hard ground but not on ice and snow. As well such vehicles are usually not capable of carrying out tasks that are frequently required by persons who travel on snowmobiles or ATV's. For example hunters commonly use tracked vehicles to reach game in dense bush. If heavy game such as moose or deer is bagged, a hoist may be required to remove the game from the bush. Most tracked vehicles lack a hoist. A hoist may also be needed by persons involved in search and rescue work in situations where a persons must be pulled from water or from crevasses.
A power takeoff (“PTO”) is a useful addition to an existing tracked vehicle in the above situations. A PTO can be used to activate a hoist, a generator and it can also be used to drive wheels on a snowmobile. In the case of a snowmobile, it is most commonly used for recreational purposes involving travel over snow-covered trails. Such trails are frequently crossed by roads which may be paved or covered by gravel. Pavement and gravel are very damaging to the runners and tracks of snowmobiles. If a snowmobile is equipped with wheels which may be lowered for use and raised when not in use, the wheels can be lowered to lift their runners and track off the ground when the vehicle is travelling over pavement or gravel and can be raised when the vehicle is travelling over snow. A PTO on a snowmobile can be used to activate the wheels.